Within the normal reproductive process, the gestation of a fetus within the female of the species typically occurs within a gestational sac. The gestational sac is comprised of a pair of juxtaposed membranes comprising an outer structure, such as the chorionic membrane (chorion) that forms an outer margin, and an inner structure, such as the amniotic membrane (amnion) which is closest proximity to the fetus. In childbirth following partuation of the gestational sac, commonly referred to as afterbirth, the membrane structure is typically disposed as medical waste. However, medical discoveries are increasingly finding valuable biomedical materials in the tissues of these materials, and specifically the amnion.
The first known clinical uses of the amnion began a century ago for the treatment of various wounds including burn trauma and skin ulcerations on the surface. Extended usage of the intact amnion and chorion tissue came in the 1950's with more focused procedures to treat skin burn sites. The value of amnion was exemplified in the 1960's with a proposal to establish an amnion bank.
Contemporary medicine has seen a relative explosion in the utility of the amnion tissue in the areas of treatment for ocular disorders and thermal and chemical burns. In these treatments, intact amnion tissue is literally transposed directly over the trauma or wound site and has been proven to promote faster healing and alleviate pain. Today the most prevalent use of amnion tissue is in surgical procedures involving the eye.
Recent research is shifting the primary focus of medical attributes to the area of stem cell derivation. The concept of “Regenerative Medicine”, which is replacing, repairing and reconstructing diseased tissue and organs by stem cell therapies, is making rapid clinical progress. Multiple stem cell populations have been identified in the amnion and chorion. When derived at child birth, the benefits can be greater because of their pristine nature due to a lack of exposure to environmental toxins. Any or all derived stem cells may have future clinical utility and may play an extremely large and beneficial role in regenerative medicine.
An alternate and proven method of stem cell derivation in current practice today, and also practiced for the benefit of regenerative medicine, is that of harvesting the placental umbilical cord blood. By this practice, a single sample of blood is harvested from the umbilical cord at birth. The harvested blood is then processed to derive the appropriate beneficial stem cells and the sample is frozen for future use. The ability to cryogenically freeze living cells for thawing and renewal at a later time is a well proven and common practice for many biological materials and is commonly used for procedures such as in vitro fertilization of embryos implanted to induce pregnancy. Cord blood, amnion and chorion tissues are likewise proven biological materials that are conducive to being frozen for an unlimited time. The stem cells derived from cord blood are typically most appropriate for the treatment of hematopoietic (i.e., blood-related) illnesses, and the singular sample retrieved will typically be saved for the future benefit of the donor. By contrast, it has been found that amnion derived stem cells possess qualities that become quite beneficial for treatment of illnesses other than hematopoietic, such as skeletal and cardiovascular. Fundamentally, umbilical cord blood produces hematopoietic stem cells and amnion and chorion produce mesenchymal and epithelial stem cells, all of which are of growing benefit to the healthcare practice of regenerative medicine and are capable of being harvested and preserved for future benefit.
With the growing number of possible clinical applications for amnion and chorion, the devices and methods used to retrieve and preserve these tissues are of increasing interest to the health care community. As new procedures are developed, the devices must be adapted and may advantageously facilitate, optimize, and simplify retrieval and storage of amnion and chorion directly from the afterbirth.